Ground-detector for insulators.



J.. WAH'N.

'GROUND DETECTOR POR INSULATORS. APPLIUATION PI LBD,PBB.2,1012.

1,995,439 Patented May 5, 191:4

l i v y narran sfrarns encreur ormoni;

JOSEF XVAHN, CIF VIENNA, AUSTRIA-HUNGARY.

GROUND-DETECTOR' FOR INSULATORS.

Louange.

Application filed February 2, 1912. Serial No. 674.932.

To aZZ whom It m r1.1/ enano/7i Be it known that I, Dr. .loser vih-inn..

Ground-Detectors for Insulators, of which the following; is aspecification.

It is the object. of the present` invention to provideian insulator and`fround detector permitting the testing of the same byl means of thenormal working current-without disconnecting th'e insulator from thecircuit. wWith this end in View a conductor (for instance a. thin metalsleeve or cap.) is emA bedded into the insulating material in' such amanner that. two distinct insulators are created, a 'main insulator anda. secondaryY insulator separatedby the conductor. By .means of thisconstruction leakage currents can be led from the conductor throughmeasuring` instruments or other devices hereinafter more fullydescribed. 1lfhe seeondary1 insulation serves as a Ahigh resistance inparallel with the measuring;- instrument or other device. Thisresistance Is so high that practically all of the leakage current isavailable for measurement or for operation of the automatic devicesreferred to later".

In the accompanying` drawing: Figure l is' a cross section of aninsulator and ground detector according` to the present invention. 'andFig. -2 shows a modified form ot'nn insulator carrier or pin with thesecondary insulator and the conductor a metal sleeve or cap). Fig. 3shows the pin head partly in section illust-ratingr the location of thefusible wire, and Fig". 4 is a cross section through the. same seen inthe direction ol" the. arrow, Fig. 3.

a is the main insulator` 'b the secondary insulator, e theeoiuluetor,'tor instance. a thin metal sleeve 'or cap, z, is anextension conductorelectrically connected with said main conductor forthe purpose, ot affording connecting` means forv a. measuring'instrument, s is the carrier or pin for the insulator.

According;` to Fig. l of the drawinn'vthe devices for automaticallyindicating' anyv de feet-s of the insulator are convenientlyy arr rangedbetween the conductor c and thc pin Specification of Letters Patent.

4.7 to the pin s.

Patented May 5, i914.

l s and consist. chieiiy of a wire cl of fusible metal connecting` themetallic cap c electrically with the pin S. The two ends of the wire (Zare fastened in the wall of the cap c and the metal part of the wire isin contact with the pin .s. The ring r is made of nonsfusible materialand rests upon the Wire (I, As longy as the wire l connects the partsand a the secondari,Y insulator (Z does not actI as a resistance for thereason that the currents coming; from the maininsulator to the metalliclayer 0 flow through the wire If the currents become so strong' thatthey meltthe wire Z they are interrupted and the secondary insulation Z)becomes active. At the same time the ring r has lost its support anddrops down. New the defect of the main insulator is detected and whennow the. hook 71, and the pin s are connected with the pole wires of ameasuring' instrument. it, is easily possible to measure the loss ofcurrent. The measuring is effected in. such a manner that the s'eeondaryinsulator acts as a large resistance shunted with the resistance of theinstrunient.

In the consti-nation according to Fig. 2 ot the drawing the fuse wire isreplaced b v an easily melting` conducting mass e in which the ring r isembedded. The mass c connects-I the part o electrically with the pin .sand has the ring#a embedded in it. It the current lbecomes so strong'that the heat generated. causes the meltingr of the mass e, the ring` isfreedand drops down.

I claim:

l. An insulator and ground detector compris-ing in combination, a maininsulator seated upon the customary pin. a secondar \7 fmleto'e, efusible Wire secured vth its callykndc'ating the presence of a leakageends lo Said conductoruncl contacting with current, substantially' asdescribed. l 10 safl pin for conduct-Wely connecting both, In testimonywhereof I affix my signature :.i, noniusble ring resting u-pon saidfusible in presence of two Witnesses.

x l l l l wire and dropping upo;L the melting of the l DR. JUSEF VVHN. same by a leakage current, and a pin upon l W'ltnesses: lle carrier 'pmfor the lnsulator adapted l/VILHELM OTTO KoPPRAscH,

lne catch said ring for visibly and Inechanl AUGUST FUGGER.

